According to one embodiment of the present specification, an STA may be connected to a primary AP and a secondary AP simultaneously. The STA may acquire control information related to whether the secondary AP can acquire a transmission/reception signal of the primary AP. Thereafter, the STA may transmit a UL signal to the primary AP. The STA may transmit, on the basis of whether the secondary AP can acquire the transmission/reception signal of the primary AP, a block acknowledgement request (BAR) signal for a UL signal to the secondary AP.